Unconscious Perception Research Articles

Mechanisms of unconscious priming: I. Response competition, not spreading activation.

Four experiments were conducted to replicate and expand upon A. G. Greenwald, S. C. Draine, and R. L. Abrams's (1996) demonstration that unconsciously perceived priming words can influence judgments of other words. The present experiments manipulated 2 types of relationships between priming and target stimuli: (a) whether priming and target stimuli possess a preexisting semantic relationship (an affective relationship in Experiments 1, 2, and 4; an associative relationship in Experiment 3; and an animacy relationship in Experiment 4) and (b) whether the primes and targets produce the same response. Large priming effects were found only when the primes and targets possessed response compatibility. No residual effects for affective, animacy, or semantic relatedness were observed. Although these results strongly support the conclusion that word meaning can be unconsciously activated, they do not support the claim that the unconscious perception effects obtained in Greenwald et al.'s (1996) paradigm are caused by automatic spreading activation of word meaning. Instead, the results reported here are consistent with a claim that unconsciously perceived words automatically trigger response tendencies that facilitate or interfere with target responding.

An experimental method for studying unconscious perception in a marketing context

An experimental method for studying unconscious perception in a marketing context

An experimental method for studying unconscious perception in a marketing context

This article provides in-depth discussion of a recently developed method designed to foster the elicitation and detection of unconscious perception. Prior findings coupled with additional studies and analyses support the value of this method as a tool for studying unconscious perception in a marketing context. The method can both divert subjects' conscious attention away from experimental stimuli and provide a separate indicator of where subjects' attentive resources are being allocated during exposure. Moreover, it is easy to use and flexibly applied in an experimental setting. © 1999 John Wiley & Sons, Inc.

Erratum to: A signal detection theory analysis of an unconscious perception effect

Erratum to: A signal detection theory analysis of an unconscious perception effect

A signal detection theory analysis of an unconscious perception effect.

The independent observation model (Macmillan & Creelman, 1991) is fitted to detection-identification data collected under conditions of heavy masking. The model accurately predicts a quantitative relationship between stimulus detection and stimulus identification over a wide range of detection performance. This model can also be used to offer a signal detection interpretation of the common finding of above-chance identification following a missed signal. While our finding is not a new one, the stimuli used in this experiment (redundant three-letter strings) differ slightly from those used in traditional signal detection work. Also, the stimuli were presented very briefly and heavily masked, conditions typical in the study of unconscious perception effects.

On demonstrating unconscious perception: comment on Draine and Greenwald (1998)

S. C. Draine and A. G. Greenwald (1998) have described a methodology based on regression analysis for demonstrating unconscious perception. They have suggested that their methodology represents a major improvement over existing methodologies. An analysis of their methodology reveals that it is closely related to the classic dissociation paradigm. As such, interpretation of their results is compromised by the same issues concerning the measurement of awareness that have plagued all previous attempts to use the dissociation paradigm to demonstrate unconscious perception in the complete absence of conscious perception.

Consciousness of perception after brain damage.

Disturbances of visual perception after brain damage provide clues to understanding consciousness and the brain. In this article we review six visual disorders in which perception and consciousness are dissociated as a result of brain damage: blindsight, implicit shape perception in apperceptive visual agnosia, covert recognition of faces in prosopagnosia, unconscious perception in neglect and extinction, implicit reading in pure alexia, and implicit object recognition in associative visual agnosia. We consider these six disorders from the standpoint of three main schools of thought concerning consciousness and the brain, namely a localized system for consciousness, consciousness as a state of integration, and consciousness as a property of graded representation. The findings suggest that these syndromes do not share a single mechanism and that it is conceivable that more than one explanation will be necessary both within and across syndromes. We conclude on the basis of the current evidence that it is unlikely that any single brain system is necessary for conscious awareness of perception that does not play a role in perception as well.

Neural and muscular electric activity in the cat's knee. Changes when the anterior cruciate ligament is transected.

We studied the response of the normal and unstable knee to passive motion and anterior tibial displacement in the cat. 6 cats were anesthetized and the deep level of anesthesia was controlled by electroencephalograms. We recorded electric activity in the articular nerves (posterior PAN and medial MAN) and periarticular muscles (quadriceps and hamstring), while performing passive flexion, extension, internal and external rotation. We then produced anterior displacement of the tibia at 30 degrees and 90 degrees of flexion, as in the Lachman and the anterior drawer maneuvers. The anterior cruciate ligament was surgically sectioned and the same series of passive displacements was performed. We observed statistically significant increased activity in the MAN, the PAN and the quadriceps muscle during knee flexion, in the MAN during extension, and in the PAN and hamstring during external rotation with the knee 90 degrees flexed. Anterior cruciate transection caused anterior displacement of the tibia during stress. This produced a significant increase in the MAN activity and a significant decrease in the hamstring electric activity at 30 degrees and 90 degrees of flexion, as in Lachman and anterior drawer maneuvers. We conclude that electric activity in the articular nerves and periarticular muscles, in response to passive motion and anterior tibial displacement, is altered in the cat's knee after anterior cruciate transection. This suggests that various patterns of periarticular muscle reaction in the anterior cruciate-deficient knee may be related to the unconscious perception of abnormal motion.

Patterns of neurotic interaction. A study of empathy and enkinesis in interpersonal relationships.

Empathy and enkinesis--its psychomotor counterpart--are described as two basic functions of the ego, responsible for such diverse patterns of interaction between person and person as sharing, resisting and complementary reactions. Both empathy and enkinesis are subject to a variety of distortions and exaggerations. If so, they may become major factors in the dynamics of neurotic family situations. Several instances of interlacing neurotic patterns, involving parent and child, are described, illustrating the importance of a tendency to sharing and to complementary reactions in the etiology of neurotic reactions in one member of the family group, while it is assumed that patterns of resisting and rebelling may tend to reduce the danger of neurotic disorder in another member, exposed to similar neurotic influences. It is pointed out that the patterns of interaction described are largely based on unconscious perception. The ways in which such intercommunication comes about are briefly discussed.

Breakthrough to awareness: a preliminary neural network model of conscious and unconscious perception in word processing.

A neural network model is constructed to mimic the processing involved in semantic and working memory when subliminal effects are involved. These effects involve modifications of reaction time to later inputs, according to whether or not there has been conscious or unconscious processing of the earlier input. The model is constructed of two separate modules: one (a semantic memory module) allowing for processing at a semantic, but unconscious, level, and the other (a working memory module) for conscious experience. The latter module, although a replica of the earlier one, has different lateral connectivity and output function from the former. The model is shown to give a good fit to Marcel's data on the processing of polysemous words. Further tests are suggested for the model, and a possible cortical implementation suggested. The relevance of the model to recent approaches to consciousness is also explored.

Breakthrough to awareness: a preliminary neural network model conscious and unconscious perception in word processing

Breakthrough to awareness: a preliminary neural network model conscious and unconscious perception in word processing

Awareness during general anesthesia. Definition, incidence, clinical relevance, causes, avoidance and medicolegal aspects

The possibility that a patient during general anaesthesia is aware of the operation going on and aware of severe pain that might be remembered postoperatively must be very alarming to patients and anaesthetists alike. Furthermore, there is experimental evidence showing that conscious recall of intraoperative events is only the tip of an iceberg; it seems very probable that there is even a higher incidence of unconscious perception during general anaesthesia. Therefore, the following stages of intraoperative awareness must be distinguished: (1) conscious awareness with explicit recall and with severe pain; (2) conscious awareness with explicit recall but no complaints of pains; (3) conscious awareness without explicit recall and possible implicit recall; (4) subconscious awareness without explicit recall and possible implicit recall; (5) no awareness. The incidence of conscious awareness with explicit recall and severe pain has been estimated at less frequent than 1/3000 general anaesthetics. Conscious awareness with explicit recall but no complaints of pain has been reported in the literature with an incidence of 05-2%. With 7-72%, conscious awareness without explicit recall and possible implicit recall shows a very wide range of variation and its occurrence probably depends on the anaesthetic drugs used. Subconscious awareness with possible implicit recall has an incidence of up to 80%, but there are many methodological problems in demonstrating implicit memory of intraoperative events. Reports of intraoperative awareness do not come exclusively from cardiac surgery and obstetrics, but also from all other operative specialties. Postoperatively, patients who experience intraoperative awareness may develop a so-called post-traumatic stress syndrome. Symptoms involve re-experiencing the event awake or in dreams, sleep disturbances, depression, avoidance of stimuli associated with the event. The probability of the development of the post-traumatic stress syndrome seems to coincide with the experience of severe pain. When a patient complains of intraoperative awareness postoperatively the anaesthesiologist should discuss the event frankly with the patient. When the symptoms of the post-traumatic stress syndrome persist a psychotherapy should follow. Causes for intraoperative awareness may be: equipment failure, too-light anaesthesia, e.g. for a caesarean section or for emergency surgery in severely injured or polytraumatized patients, during cardiac surgery, bronchoscopy of difficult intubation. There is interindividual variability in anaesthetic effect; for example, chronic drug or alcohol abuse or overweight may make increased anaesthetic doses necessary. They are at risk for intraoperative awareness. Some general anaesthetics or anaesthetic procedures, e.g. the combination of a relaxant and N2O, opioid mono-anaesthetics, or opioids combined with benzodiazepines, seem to involve a higher risk of intraoperative awareness than do volatile anaesthetics. The bases of litigation are medical malpractice, breach of contract by the anaesthesiologist or lack of informed consent from the patient. Therefore, patients who are at risk of intraoperative awareness should be given detailed information on this special risk before the operation.

Implications of early hominid labyrinthine morphology for evolution of human bipedal locomotion.

The upright posture and obligatory bipedalism of modern humans are unique among living primates. The evolutionary history of this behaviour has traditionally been pursued by functional analysis of the postcranial skeleton and the preserved footprint trails of fossil hominids. Here we report a systematic attempt to reconstruct the locomotor behaviour of early hominids by looking at a major component of the mechanism for the unconscious perception of movement, namely by examining the vestibular system of living primates and early hominids. High-resolution computed tomography was used to generate cross-sectional images of the bony labyrinth. Among the fossil hominids the earliest species to demonstrate the modern human morphology is Homo erectus. In contrast, the semicircular canal dimensions in crania from southern Africa attributed to Australopithecus and Paranthropus resemble those of the extant great apes. Among early Homo specimens, the canal dimensions of Stw 53 are unlike those seen in any of the hominids or great apes, whereas those of SK 847 are modern-human-like.

Unconscious perception: attention, awareness, and control.

Conscious perception is substantially overestimated when standard measurement techniques are used. That overestimation has contributed to the controversial nature of studies of unconscious perception. A process-dissociation procedure (L. L. Jacoby, 1991) was used for separately estimating the contribution of conscious and unconscious perception to performance of a stem-completion task. Unambiguous evidence for unconscious perception was obtained in 4 experiments. In Experiment 1, decreasing the duration of a briefly presented word diminished the contribution of both conscious and unconscious perception. In Experiments 2-4, dividing attention reduced the contribution of conscious perception while leaving that of unconscious perception unchanged. Discussion focuses on the measurement of awareness and the relation between perception and memory.

Unconscious perception: Attention, awareness, and control.

Conscious perception is substantially overestimated when standard measurement techniques are used. That overestimation has contributed to the controversial nature of studies of unconscious perception. A process-dissociation procedure (L. L. Jacoby, 1991) was used for separately estimating the contribution of conscious and unconscious perception to performance of a stem-completion task. Unambiguous evidence for unconscious perception was obtained in 4 experiments. In Experiment 1, decreasing the duration of a briefly presented word diminished the contribution of both conscious and unconscious perception. In Experiments 2-4, dividing attention reduced the contribution of conscious perception while leaving that of unconscious perception unchanged. Discussion focuses on the measurement of awareness and the relation between perception and memory.

The relationship between conscious and unconscious influences: Independence or redundancy?

Determining the relationship between conscious and unconscious influences is essential for obtaining valid estimates of the 2 types of influence. S. Joordens and P. M. Merikle (1993) recently argued that a redundancy relationship provides a plausible alternative to the independence model proposed by L. L. Jacoby, J. P. Toth, and A. P. Yonelinas (1993). In this article, the authors address Joordens and Merikle's concerns and still find the independence model preferable: First, the redundancy model requires the questionable assumption that a direct test (inclusion) is process pure. Second, results obtained with the independence model, but not with the redundancy model, converge with results from indirect tests. Finally, conclusions drawn from the independence model are in accordance with the theorizing that surrounds the concept of automaticity. Findings of task dissociations have been important for theorizing about both unconscious perception and unconscious influences of memory (implicit memory). People show evidence of perception and memory on indirect tests although they are seemingly unaware of the event that gave rise to those effects when given a direct test (e.g., Roediger & McDermott, 1993). However, Reingold and Merikle (1990), as well as we (Jacoby, Toth, & Yonelinas, 1993) have argued against the practice of equating unconscious influences with performance on indirect or implicit tests and conscious influences with performance on direct or explicit tests. The difficulty is that conscious processes might contaminate performance on indirect tests and, less obviously, unconscious processes might contaminate performance on direct tests. Consequently, we have sought process dissociations rather than task dissociations. That is, rather than equating processes with tasks, our strategy has been to gain estimates of the contributions of conscious and unconscious processes to performance of a single task and to show dissociations of effects of variables on those estimates.

Dissociated overt and covert recognition as an emergent property of a lesioned neural network.

Covert recognition of faces in prosopagnosia, in which patients cannot overtly recognize faces but nevertheless manifest recognition when tested in certain indirect ways, has been interpreted as the functioning of an intact visual face recognition system deprived of access to other brain systems necessary for consciousness. The authors propose an alternative hypothesis: that the visual face recognition system is damaged but not obliterated in these patients and that damaged neural networks will manifest their residual knowledge in just the kinds of tasks used to measure covert recognition. To test this, a simple model of face recognition is lesioned in the parts of the model corresponding to visual processing. The model demonstrates covert recognition in 3 qualitatively different tasks. Implications for the nature of prosopagnosia, and for other types of dissociations between conscious and unconscious perception, are discussed.

Indeterminacy and consciousness in the creative process: What quantum physics has to offer

Abstract The quantum view of creativity, based on Goswami's idealistic interpretation of quantum physics, is presented. It provides a resolution for two controversial areas of creativity theory and research: the “aha”; experience and the role of consciousness. According to the quantum model, the mind‐brain consists of classical and quantum functions and structures. The source for creative ideation lies in the quantum realm in the form of unlearned coherent superpositions or states of simultaneous multiple possibilities. While access of coherent superpositions (CohS) are susceptible to interference from classical domain functions, such as attention, the CohS itself is experienced as an altered state, facilitating creative ideation. The relationships among attention, self‐awareness, context, ambiguity, uncertainty, and conscious and unconscious perception in creative ideation are proposed to be experienced discontinuously due to an indeterminate element inherent in nature. Theoretical and empirical investigation of the above propositions is possible through quantum physics.

Unintended influences of perception and memory: Attention, awareness, and control.

There has been a great deal of recent interest in the finding of dissociations between performance implicit or indirect and explicit or direct tests of memory. Implicit tests (e.g., word stem completion) are said to primarily reflect automatic or unconscious uses of memory, whereas explicit tests (e.g., cued recall) primarily reflect strategic or consciously - controlled uses of memory. I argue that implicit tests of perception and memory share important characteristics with projective tests, such as the Rorschach test, that have traditionally been used to gain evidence of unconscious influences. For projective tests as well as implicit tests, it is dissociations with performance direct tests that provide evidence of unconscious influences. A Rorschach test is said to provide evidence of inner conflicts that could not be revealed by directly asking the person about those conflicts. Similarly, an implicit test of memory sometimes reveals evidence of memory, although when directly asked, a person is unable to report the relevant memory.Implicit and projective tests also share problems for interpretation. The major problem is that of relating processes to tasks. Most of us are not tempted to treat a Rorschach test as if it measures only unconscious influences. We realize that people may sometimes catch - on to the intent of a projective test, and fake performance. That is, we are convinced that a Rorschach test is not factor or process pure. Similarly, for the stem - completion task and other implicit tests of memory, people may sometimes intentionally use memory. Problems arising from the possibility of contamination of a supposed measure of unconscious influences is most obvious in the case of unconscious perception. The history of that area has been an apparently never ending circle of claimed demonstrations of unconscious perception, followed by disqualifying claims of contamination. Of course, it is well known that tests of unconscious perception sometimes reflect aware perception and that tests of implicit memory sometimes reflect intentional uses of memory. This possibility of contamination does, though, produce serious problems for interpretation. One strategy is to further refine the measure of unconscious influences in an attempt to produce a test that is process pure. This has been the strategy in investigations of unconscious perception and, to a lesser extent, in studies of implicit memory. However, it may be impossibleto construct a test of unconscious influences that is never contaminated by intentional uses of memory. …

Auditory Perception and Sound Source Determination

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